Functions running too often on page load and callback

[wtluke]

On page load, Dash serves the initial layout (when provided in a function) more than once. I've seen it run one of my "initial" functions at least 20 times. Likewise, if you have 5 inputs, a callback's function is running 5 times even if not all of those inputs have changed or fired. Caching has helped, but it still seems really inefficient and others have noticed similar behaviour.

Have a look here for more details.